Where to Buy Alum in the UK: Pharmacies, Supermarkets & Online

Alum (potassium aluminum sulfate) is available in several forms (block, powder, crystal) from these UK sources:

🏥 Pharmacies & Chemists

• Boots, Superdrug, LloydsPharmacy, Well — often in first-aid or footcare sections (as styptic pencil/powder).
• Independent pharmacies — may order if not in stock.

🛒 Supermarkets (Larger Branches)

• Tesco, Sainsbury's, Asda, Morrisons — baking aisle (pickling/crisping agent) or household cleaning (mordant, deodorant). Look for "alum powder" or "pickling alum."

🌿 Health Food & Natural Stores

• Holland & Barrett, Planet Organic, Whole Foods Market, independent health shops — sold as natural deodorant crystal (potassium alum block) or powder.

🌐 Online Retailers (Widest Selection)

• Amazon UK, eBay UK — food-grade, cosmetic-grade, technical-grade; blocks, powders, crystals.
• Specialist chemical suppliers: Chemist Direct, Mistral, The Soap Kitchen, Just Ingredients.
• Craft/soap-making sites: Soap Kitchen, The Soapery.

⚠️ Critical: Buy the Right Grade

• Food-grade (E522): For pickling, baking, water purification.
• Pharmaceutical/cosmetic-grade: For deodorant, aftershave, styptic.
• Industrial/technical-grade: For dyeing, tanning, water treatment — NOT for body/food use.

Always check labeling. A 100g food-grade block costs £3–£6; 1kg powder £10–£15.